Quantitative histological analysis of bovine small intestines before and after processing into natural sausage casings

A histological study was undertaken to determine the efficiency in the removal of the mucosa and Peyer's patches by standard processing of bovine intestines into natural sausage casings. The second objective was to calculate the quantity of lymphoid and nervous tissue per consumable sausage. For the histological analysis, intestinal samples were collected from 80 beef cattle during the slaughter process. Fresh and cleaned intestines were compared in analyzing the thickness of the intestinal wall, weight reduction during cleaning, removal of the mucosal layer, and the presence of lymphoid and neural tissue after cleaning. The obtained data indicate a weight reduction of about 50% during standard cleaning procedures, as 90% of the mucosa and 48% of the lymphoid tissue are removed. Based on the quantitative histological image analysis, it was calculated that 1 m of cleaned casings, weighing on average 64 g, contains about 2.8 g of mucosa, 0.3 g of lymphoid tissue, and 0.1 g of neural tissue. Assuming, in a worst-case scenario, that the sausage casing is ingested when consuming 200 g of sausage at one meal, this consumption includes 0.09 g of lymphoid tissue and 0.02 g of neural tissue as part of the sausage casing. These data can be included in a risk assessment on the potentialexposure of consumers to bovine spongiform encephalopathy infectivity after eating sausages in beef casings.     

Short communication: Parameters of abomasal emptying and glucose-insulin dynamics in Holstein-Friesian calves at 2 ages and 2 levels of milk replacer intake

Elevated planes of nutrition in the preweaning period of dairy calf management can increase average daily gain, shorten age at puberty, and increase milk yield. In a previous study, 12 Holstein calves were fed 2 meals/d of 4 or 2 L milk replacer up to 7 wk of age. The objective of the current study was to estimate parameters of abomasal emptying and glucose-insulin dynamics in these calves by fitting a mechanistic model to postprandial appearances of plasma glucose, insulin, and the abomasal emptying marker acetaminophen measured at 4 and 7 wk of age. Higher intake of milk replacer resulted in longer bouts of abomasal emptying at a slower rate. Parameters of glucose and insulin dynamics were not affected by milk replacer intake. However, older calves had decreased insulin-stimulated glucose utilization indicating impaired insulin sensitivity, as well as increased pancreatic responsiveness. Neither of these effects were apparent from i.v. glucose tolerance tests on the calves and may have been related to postprandial gut hormone release. Effects of age on parameters of glucose-insulin dynamics were larger than effects of milk replacer intake. Conversely, effects of milk replacer intake on abomasal emptying were larger than effects of age.     

Ascorbic acid and dehydroascorbic acid content of blanched sweet green pepper during chilled storage in modified atmospheres

Sweet green pepper (Capsicum annuum L.) cut into pieces was analysed for ascorbic acid (AA) and dehydroascorbic acid (DHAA) content before and after blanching, after 1, 4 and 7 days of chilled storage in modified atmosphere, and after reheating. No difference in retention of AA was noted between storage in 2 and 4% O₂ atmospheres, whereas retention during storage in air was significantly lower. Production of DHAA during storage increased with increased O₂ content in the atmosphere. After 7 days of storage, DHAA contributed 10–35% of the total AA, and DHAA contributed 12–25% after reheating, depending on the O₂ content in the atmosphere. Since the vitamin activity of DHAA is considered to be the same as that of AA, it is concluded that the content of DHAA in processed green pepper is of importance and should be measured together with AA.

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Gehalt an Ascorbinsäure und Dehydroascorbinsäure in blanchiertem grünem Pfeffer nach Kühllagerung in modifizierter Atmosphäre

Zusammenfassung Der Gehalt an Ascorbinsäure und Dehydroascorbinsäure in Stücken von grünem Pfeffer (Capsicum annuum L.) wurde vor und nach einer Blanchierung nach bzw. 1, 4 und 7 Tagen Kühllagerung in modifizierter Atmosphäre sowie nach Wiedererhitzung bestimmt. Es war kein Unterschied in der Ascorbinsäureretention bei Lagerung in Atmosphären mit 2 und 4% Sauerstoff zu verzeichnen, während die Retention bei Luftlagerung signifikant geringer war. Die Bildung von Dehydroascorbinsäure bei Lagerung war höher mit steigendem Sauerstoffgehalt in der Atmosphäre. Die Dehydroascorbinsäure betrug nach 7 Tagen Lagerung 10–35% der gesamten Menge an Ascorbinsäure und 12–25% nach Wiedererhitzung abhängig vom Sauerstoffgehalt in der Atmosphäre. Wenn die Vitaminaktivität der Dehydroascorbinsäure gleich hoch wie die der Ascorbinsäure gehalten wird, ist daraus zu schließen, daß der Gehalt an Dehydroascorbinsäure in verarbeitetem grünen Pfeffer von Bedeutung ist und daher zusammen mit dem Ascorbinsäure-Gehalt beurteilt werden sollte.

     

Loss of Microglial Insulin Receptor Leads to Sex-Dependent Metabolic Disorders in Obese Mice

Obesity and type 2 diabetes mellitus (T2DM) are highly prevalent disorders, associated with insulin resistance and chronic inflammation. The brain is key for energy homeostasis and contains many insulin receptors. Microglia, the resident brain immune cells, are known to express insulin receptors (InsR) and to be activated by a hypercaloric environment. The aim of this study was to evaluate whether microglial insulin signaling is involved in the control of systemic energy homeostasis and whether this function is sex-dependent. We generated a microglia-specific knockout of the InsR gene in male and female mice and exposed them to control or obesogenic dietary conditions. Following 10 weeks of diet exposure, we evaluated insulin tolerance, energy metabolism, microglial morphology and phagocytic function, and neuronal populations. Lack of microglial InsR resulted in increased plasma insulin levels and insulin resistance in obese female mice. In the brain, loss of microglial InsR led to a decrease in microglial primary projections in both male and female mice, irrespective of the diet. In addition, in obese male mice lacking microglial InsR the number of proopiomelanocortin neurons was decreased, compared to control diet, while no differences were observed in female mice. Our results demonstrate a sex-dependent effect of microglial InsR-signaling in physiology and obesity, and stress the importance of a heterogeneous approach in the study of diseases such as obesity and T2DM.     

EUROPEAN SILVER EEL MIGRATION AND FISHERIES‐INDUCED MORTALITY IN THE HAVEL RIVER SYSTEM (GERMANY)

By using acoustic telemetry, the behaviour and fishery mortality of silver eels Anguilla anguilla (L.) were studied during the early phase of the spawning migration through the Havel River downstream to the river Elbe. A total of 99 female silver eels were implanted with acoustic transmitters and released at two locations in the Havel River system in autumn 2007. Tag recaptures by fisheries were used to assess fishery mortality. Most eels continued their downstream migration immediately after release during October–November in the year of release. However, some eels continued their downstream migration the following spring or autumn; only a few eels migrated in winter and summer. Tagged eels reached the river Elbe from 2 days to more than 1 year after tagging. Fishing efficiency was very high, and by the end of December 2008, only 8% of the tagged eels had reached the river Elbe, whereas 25% were reported caught by commercial fishers and 2% by recreational fishers. The remaining 65% of the tagged eels were unaccounted for at the end of the study period. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of fat inclusion in starter feeds for dairy calves by mixing increasing levels of a high-fat extruded pellet with a conventional highly fermentable pellet

The objective of this study was to evaluate the effect of inclusion of an extruded high-fat pellet mixed with a conventional pelleted calf starter on energy intake and performance around weaning in calves. To this end, 75 female Holstein newborn calves (41.0 ± 4.98 kg) were randomly assigned to 1 of 5 iso-nitrogenous solid feed treatments consisting of 4 levels of fat inclusion by mixing a low-fat highly fermentable control pellet with 3 different levels of inclusion of an extruded high-fat pellet [control (100:0), 90:10, 80:20, and 70:30], and a high-fat single pellet (HFSP). The HFSP was equivalent iso-energetic and iso-nitrogenous, although it had almost 1 percentage point difference in fat relative to the 80:20 treatment, to contrast the effect of the dual-component pellet mixture. The extruded high-fat starter feed contained a high proportion of fat (38%), mainly from hydrogenated palm fatty acids. Calves were offered a milk replacer up to 900 g/d, and then pre-weaned at 49 d of age by halving milk allowance until 56 d when calves were weaned. Calves had ad libitum access to the starter diets, chopped straw, and water. Individual milk replacer and starter intakes were recorded daily and BW was determined weekly. A glucose tolerance test was performed at 49 and 84 d of age to evaluate blood glucose homeostasis. Apparent total-tract digestibility was determined from 70 to 75 d of age. Calves on the 90:10 treatment had greatest starter feed intake mainly due to a marked increase in solid feed intake around weaning. Metabolizable energy intake was increased when the extruded pellet was included in the starter. No differences were present in digestibility of ether extract among solid feed treatments. The area under the curve of blood glucose concentration after the glucose tolerance test was greatest in 80:20; intermediate in 70:30, HFSP, and control; and lowest in 90:10 calves. No differences were observed for insulin or other parameters related to blood glucose homeostasis. Delivering dietary fat by mixing an extruded high-fat pellet with a conventional highly fermentable pellet to reach a total fat content of 7% results in increased starter intake, energy intake, and body weight gain until 84 d of age compared with a conventional low-fat pellet, or a single pellet with increased fat content.     

Koji fermentation based on extracellular peptidases of <Emphasis Type="Italic">Flammulina velutipes</Emphasis>

A total of 28 basidiomycetes and 16 substrates were investigated to detect extracellular peptidases for the hydrolysis of wheat gluten as a complex Koji substrate. In a first screening, basidiomycetes were grown in submerged cultures containing gluten as only carbon and nitrogen source. Growth rate, protein concentration and peptidase activity were monitored. Flammulina velutipes, Armillaria mellea, Trametes versicolor, Meripilus giganteus, Fomitopsis pinicola, Phanerochaete chrysosporium and Hericium erinaceus showed high peptidase activity. To evaluate the effects of complex substrates on peptidase generation, a set of experiments was performed using surface cultures of Flammulina velutipes. This fungus grew well on many of the substrates and yielded a maximum of over 160.000 arbitrary U mL⁻¹ on the surface liquid released from gluten pellets. Gelatin zymography visualized a complex mixture of secreted peptidases. Highest peptidase yield was obtained from a koji-type culture: A maximum of 63% of the gluten was converted to free amino acids in 14 days by peptidase activities in the range of 80,000–90,000 aU mL⁻¹. The dark brown hydrolysate smelled and tasted like meat broth with no detectable bitterness.     

The effect of NMDA receptors on gain modulation

The ability of individual neurons to modulate the gain of their input-output function is important for information processing in the brain. In a recent study, shunting inhibition was found to modulate the gain of cerebellar granule cells subjected to simulated currents through AMPA receptor synapses. Here we investigate the effect on gain modulation resulting from adding the currents mediated by NMDA receptors to a compartmental model of the granule cell. With only AMPA receptors, the changes in gain induced by shunting inhibition decreased gradually with the average firing rate of the afferent mossy fibers. With NMDA receptors present, this decrease was more rapid, therefore narrowing the bandwidth of mossy fiber firing rates available for gain modulation. The deterioration of gain modulation was accompanied by a reduced variability of the input current and saturation of NMDA receptors. However, when the output of the granule cell was plotted as a function of the average input current instead of the input firing frequency, both models showed very similar response curves and comparable gain modulation. We conclude that NMDA receptors do not directly impair gain control by shunting inhibition, but the effective bandwidth decreases as a consequence of the increased total charge transfer.     

EXCALIBUR — a Monte Carlo program to evaluate all four-fermion processes at LEP 200 and beyond

A Monte Carlo program is presented that computes all four-fermion processes in e⁺e⁻ annihilation. QED initial state corrections and QCD contributions are included. Fermions are taken to be massless, allowing a very fast evaluation of the matrix element. A systematic, modular and self-optimizing strategy has been adopted for the Monte Carlo integration, which serves also as an example for further event generators in high energy particle physics.